Research Update on Stress Riser Fractures

Abstract

Stress fractures are fatigue-induced fractures which are caused by repetitive force, often from overuse. They are well-established and frequently encountered in the field of orthopedics. Stress fractures occur in the bone because of low-bone strength and high chronic mechanical stress placed on the bone. Stress riser fractures are also stress fractures that occur because of the presence of cortical defects (holes), changes in stiffness, sharp corners, and cracks (fracture lines). Periprosthetic or peri-implant fractures are good examples of stress riser fractures that occur in regions where stress forces are higher than those in the surrounding material. Most stress riser fractures are related to technical errors (iatrogenic causes) and are difficult to manage. It is possible and more effective to prevent the creation of stress riser fractures through better surgical techniques. The proper terminology for stress fractures, stress riser fractures, periprosthetic fractures, peri-implant fractures, interprosthetic fractures, and interimplant fractures is discussed. This review of the current state of knowledge, diagnosis, treatment, and prevention of stress riser fractures is based on clinical evidence and recent literature.

Keywords: Interimplant fracture; Interprosthetic fracture; Peri-implant fracture; Periprosthetic fracture; Stress fracture; Stress riser fracture.

Fig. 1

A sketch map and real photos show the factors that lead to stress riser fractures. The crack from the hole is a good example of stress riser fractures, and the crack is propagated from the sharp corner

Fig. 2

An empty guide pin (2.8 mm) hole was left in the subtrochanteric area during femoral neck fracture fixation with cannulated screws. The secondary subtrochanteric fracture occurred in the stress riser of the empty hole

Fig. 3

Risk factors in stress riser fractures as a change of stiffness (“Young’s modulus” fracture). a The upper most bicortical locking head screw had a role in stress concentration; b A dual plate at same level can make a stress concentration

Fig. 4

The authors performed an arthroplasty due to hip pain in a 74-year-old female patient with Paget’s disease. The hairline crack (arrow) became progressively worse every month. A stress riser fracture occurred in the subtrochanteric area 6 months after the operation

Fig. 5

a An 81-year old woman was fixed with two cannulated screws. b A bone scan was useful to detect the impending stress riser fracture. c The stress riser fracture occurred from the screw hole. d We reduced the fracture gap by the proximal femoral nail

Fig. 6

Empty screw holes were left just around the tip of the stem. It can be a risk factor for periprosthetic stress riser fractures

Fig. 7

a An 87-year-old female patient who had a distal ipsilateral femoral fracture from a previous operation using an intramedullary nail for a trochanteric fracture; b the operation with a locking compression plate was conducted; c The patient suffered a fracture between the old nail and the new plate only 1 week after the operation; d the removal of the previous hip nail was performed and a Huckstep nail was inserted